Sneaking Spies Into a Cell's Nucleus
ScienceDaily (Sep. 28, 2010) — Duke University bioengineers have not only figured out a way to sneak molecular spies through the walls of individual cells, they can now slip them into the command center -- or nucleus -- of those cells, where they can report back important information or drop off payloads.
Tuan Vo-Dinh, left, and Molly Gregas are researchers at Duke University. (Credit: Duke University Photography)
Using silver nanoparticles cloaked in a protein from the HIV virus that has an uncanny ability to penetrate human cells, the scientists have demonstrated that they can enter the inner workings of the nucleus and detect subtle light signals from the "spy."
In order for these nano-spies to be effective, they not only need to get through the cell's first line of defense -- the cell wall -- they must be able to enter the nucleus.
The ultimate goal is to be able to spot the earliest possible moment when the genetic material within a cell begins to turn abnormal, leading to a host of disorders, especially cancer.
The finding also shows how drugs or other payloads might be delivered directly into the nucleus.
"This new method of getting into and detecting exactly what is going on in the nucleus of cell has distinct advantages over current methods," said Molly Gregas, a graduate student in the laboratory of Tuan Vo-Dinh, R. Eugene and Susie E. Goodson Distinguished Professor of Biomedical Engineering, professor of chemistry and director of The Fitzpatrick Institute for Photonics at Duke's Pratt School of Engineering.
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Read more here/Leia mais aqui: Science Daily
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Nanomedicine: Nanotechnology, Biology and Medicine
Characterization of nanoprobe uptake in single cells: spatial and temporal tracking via SERS-labeling and modulation of surface charge
Molly K. Gregas a, b, Fei Yan a, b, Jonathan Scaffidi a, b, Hsin-Neng Wang a, b and Tuan Vo-Dinh a, b, c, ,
a Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, NC, USA 27708-0281
b Fitzpatrick Institute for Photonics, Duke University, 136 Hudson Hall, Box 90281, Durham, NC, USA 27708-0281
c Department of Chemistry, Duke University, 136 Hudson Hall, Box 90281, Durham, NC, USA 27708-0281
Received 21 August 2009;
revised 1 March 2010;
accepted 23 July 2010.
Available online 3 September 2010.
Abstract
A critical aspect for use of nanoprobes in biomedical research and clinical applications involves fundamental spatial and temporal characterization of their uptake and distribution in cells. Raman spectroscopy and two-dimensional Raman imaging were used to identify and locate nanoprobes in single cells using surface-enhanced Raman scattering (SERS) detection. To study the efficiency of cellular uptake, silver nanoparticles functionalized with three different positive-, negative-, and neutrally-charged Raman labels were co-incubated with cell cultures, and internalized via normal cellular processes. The surface charge on the nanoparticles was observed to modulate uptake efficiency, demonstrating a dual function of the surface modifications as tracking labels and as modulators of cell uptake. These results indicate that the functionalized nanoparticle construct has potential for sensing and delivery in single living cells, and that use of SERS for tracking and detection is a practical and advantageous alternative to traditional fluorescence methods.
Keywords: nanoprobes; cellular uptake; surface enhanced Raman scattering; Raman spectroscopy; nanoparticles
Corresponding author. Tel.: 919 660 8520; fax: 919 613 9145.
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